1. Field of the Invention
The present invention relates to a refrigerator, and more particularly, to a refrigerator having a cool air dispersing device capable of dispersing cool air supplied into a cooling compartment horizontally and vertically, and preventing backflow of air in the cooling compartment toward an evaporator.
2. Prior Art
In general, a refrigerator has a cabinet for forming a pair of cooling compartments, i.e., a freezing compartment and a fresh food compartment which are partitioned by a partitioning wall, a freezing compartment door and a fresh food compartment door for opening/closing the cooling compartments respectively, and a cooling system for supplying the freezing compartment and the fresh food compartment with cool air which is comprised of a compressor, a condenser and an evaporator. The cool air generated by the evaporator flows along a cool air duct formed in a rear wall of each compartment, and then is supplied into each cooling compartment by a blowing fan through cool air discharge ports opened thereinto.
In such a conventional refrigerator, however, there exist an area on which the cool air discharged through the cool air discharge ports is concentrated, and an area to which a relatively small amount of cool air is supplied, so there occurs a deviation of temperature in the cooling compartments and uniform cooling cannot be achieved. Therefore, the refrigerator adopting so called tri-dimensional cooling method which has amended such a problem has been proposed. In the refrigerator adopting the tri-dimensional cooling method, the cool air discharge ports are provided at both side walls as well as at the rear wall of the cooling compartment in order to promote the uniform cooling.
However, in such a refrigerator adopting the tri-dimensional cooling method, since the cool air is discharged through the cool air discharge ports in fixed directions, there may be a dead-zone at an edge area which is not supplied with the cool air sufficiently. In particular, since the cool air duct has to be provided not only in the rear wall but also in the side walls, there are problems that the space for storing food is reduced and the manufacturing cost increases due to the increased number of components and processes.
The uniform distribution of cool air has risen to an important problem in relation to the trend to use large-sized refrigerators.
In consideration of such a problem, the applicant of this invention has proposed a refrigerator having a device for dispersing cool air in International Patent Application WO 95/27278. FIGS. 1 through 3 are a side view, a partial enlarged sectional view, and an exploded perspective view of main elements of the refrigerator having the device for dispersing cool air.
The conventional refrigerator having the device for dispersing cool air has a pair of cooling compartments 2 and 3 in a cabinet 1 with hexahedral shape, which are partitioned from each other by a partitioning wall 5. The cooling compartments 2 and 3 are called a freezing compartment 2 of relatively low temperature and a fresh food compartment 3 of relatively high temperature. On the front opening of the cooling compartments 2 and 3, doors 6 and 7 for opening/closing them are installed respectively. In the cabinet 1 is installed a cooling system comprising a compressor 11, a condenser (not shown), a freezing compartment evaporator 12a, and a fresh food compartment evaporator 12b. The cool air generated from the evaporators 12a and 12b is supplied to the corresponding compartments 2 and 3 by a freezing compartment fan 13a and a fresh food compartment fan 13b respectively.
A duct plate 9 of partial cylinder shape having cool air discharge ports 16 opened to the fresh food compartment 3 is attached to an inner wall plate 23 forming a rear inner wall surface of the fresh food compartment 3, and a cool air duct 15 and a circulation duct 17 separated from each other by a seal plate 25 are provided between the duct plate 9 and a rear wall 4 of the cabinet 1. In the cool air duct 15 is installed a duct member 21 for guiding the cool air blown by the fresh food compartment fan 13b downwardly. The cool air generated by the fresh food compartment evaporator 12b is blown by the fresh food compartment fan 13b, and then supplied to the fresh food compartment 3 via the cool air duct 15 and the cool air discharge ports 16.
A cool air dispersing device 130 is installed in the cool air duct 15. The cool air dispersing device 130 is comprised of a rotational shaft 131 having a vertical axis, cool air dispersing blades 132 assembled with the rotational shaft 131 at areas adjacent to the cool air discharge ports 16 respectively, and a driving motor 135 for rotating the rotational shaft 131. Each of the cool air dispersing blades 132 is comprised of three discs 136, 137 and 138 disposed in parallel with each other along the axis direction, and a first blade part 133 and a second blade part 134 disposed between the discs 136, 137 and 138. Each of the blade parts 133 and 134 are bent so that their cross section is a lax shape of alphabet S. The blade parts 133 and 134 are bent to the opposite directions to each other.
In the refrigerator having the above-described constitution, when the driving motor 135 rotates the rotational shaft 131 at a low speed, the cool air flowing along the cool air duct 15 changes its flowing direction along the bent surface of the cool air dispersing blades 132, and is discharged into the fresh food compartment 3 to be dispersed horizontally. Meanwhile, when the concentrative cooling on a specific area is needed, the driving motor 135 stops the rotational shaft 131 in accordance with the direction of the cool air dispersing blades 132 so that the cool air is concentrated on the specific area.
However, since the blade parts 133 and 134 of the cool air dispersing device 130 are bent to be shaped into the lax alphabet S, the smooth flow of cool air may be impeded by a vortex of the cool air formed about the cool air discharge ports 16.
Moreover, although such a conventional cool air dispersing device 130 can achieve the uniform distribution of the cool air horizontally, the vertical distribution of the cool air has not been be uniform sufficiently, so there is a limitation in realizing the uniform cooling through the overall area of the fresh food compartment 3.
Moreover, in such a conventional refrigerator, since the cool air discharge ports 16 are open always, relatively warm air in the fresh food compartment 3 may flows back toward the evaporator 12b, which may cause the generation of frost on the evaporator 12b. When the frost is generated on the evaporator 12b, the heat exchange efficiency of the evaporator 12b is lowered, and therefore, the cooling efficiency of the overall cooling system is lowered.
Furthermore, in order to remove the frost, the evaporator has to be heated using an additional defrosting heater (not shown), so the cooling efficiency is more lowered, and consumption of electrical power increases.